Even the rattiest sneaker can become an energy-harvesting powerhouse, thanks to an ultrathin crystal chip that converts footfalls into electricity. Developed by Anthony Mutua, a recent graduate of Mombasa Polytechnic University College , the device generates a charge large enough to power a cellphone when it's subjected to pressure, say from the act of walking or running. The technology is so promising, in fact, that Kenya’s National Council of Science and Technology , which funded Mutua’s prototype, is bankrolling its commercial production.